The present invention concerns limiting access to a below grade shut off valve controlling a utility service to an individual customer for use by water, gas or other utilities. Such shut off valves are provided to enable utility personnel to shut off service as to nonpaying customers or for servicing the plumbing connections to a customer, etc. The shut off valves are located a sufficient distance below the surface in order to avoid freeze up in the case of a water supply utility. A cover is attached to the open top of a curb box located at the surface with a stand pipe extending down to a shut off valve. Despite its name, such curb boxes may be round as shown in the drawings. A pentagonal head security bolt is currently used to secure the cover in place, the bolt advanced through a hole in the cover and into a threaded hole formed in an integral flange projecting radially inwardly from a perimeter wall of the curb box. The special pentagonal wrenches needed to remove such a bolt are in very widespread use and are readily obtained by members of the public. It is easy for a nonpaying customer to obtain such a wrench, remove the security bolt and cover, and turn the water back on. Sometimes a customer will fill the curb box and perhaps the stand pipe as well with concrete to prevent utility personnel from again shutting off the water which actions creates a considerable challenge to service personnel to undo.
A more sophisticated security cover screw is now available commercially such as from Bryce Fastener of Gilbert Ariz., which uses a customized key mating with features arranged in an annular space of a shape unique to a given utility company, which keys are not easily available to a member of the general public. This reduces the problem created by reliance on an easily obtained wrench having a pentagonal shape. However, the cover is still vulnerable to being pried off or broken open.
In addition, due to the frequent great age of such fittings, the flange normally having a threaded hole receiving the security bolt is often damaged to a degree such that no threaded fastener can be effectively held in the threaded hole.
Another problem is that holes may be drilled into the bolt head or to the access cover itself to enable prying the cover to enable its forcible removal and thereby allow unauthorized access to the shut off valve.
It is an object of the present invention to provide an improved combination of a cover assembly connected to a prior art curb box by a much more rugged and effective means than by a security bolt installed in the flange threaded hole, as described above. This improved combination can render the security cover less vulnerable to being pried out or broken open to prevent unauthorized access to a shut off valve.